Aspects of the invention can relate to a manufacturing method of a sub-mirror, a manufacturing method of a light source lamp, a projector, and a manufacturing method of a piercing part.
In a related art light source lamp used in a projector, a light source lamp provided with a sub-mirror to reflect lights, emitted from an arc tube toward an illuminated region, to a reflector. By using this light source lamp, it is possible to effectively use lights that are emitted from the arc tube toward the illuminated region to be otherwise used ineffectively. Luminance of the projector, therefore, can be improved further, see, for example, JP-A-8-31382 (FIG. 1 and FIG. 3) and JP-A-11-143378 (FIG. 1 and FIG. 2).
FIG. 9 is a view showing the structure of a related art light source lamp disclosed in JP-A-8-31382 (FIG. 1 and FIG. 3). FIG. 10 is a view showing the structure of a light source lamp disclosed in JP-A-11-143378 (FIG. 1 and FIG. 2). With the light source lamp 810/910, lights emitted from an arc tube 812/912 toward an illuminated region are reflected on a sub-mirror 813/913 to a reflector, and can be thereby used effectively.
Incidentally, it is preferable that the sub-mirror is made of a high heat resistant material, because an output from the arc tube is increased as luminance of the projector becomes higher. It is also preferable that the sub-mirror is made of a material transmitting UV lights and infrared lights that are not needed for illumination in controlling a rise in temperature in the vicinity of the arc tube by improving efficiency of heat dissipation of illumination lights. To this end, materials, for example, vitreous silica, light-transmissive alumina, sapphire, ruby, and the like, may be used as the material of such a sub-mirror.